Monk's extradition to the UK for alleged drug trafficking offences has now been put on hold while police investigate his alleged links to the murder of 25-year-old Liverpool man Francis Brennan.

Mr Brennan vanished in January 2014 after being kidnapped in Alicante by three men disguised as police officers. His body was discovered in a heavily-taped plastic bag on Zenia beach in Orihuela in March 2014.

The Guardia Civil said Monk was an associate of Paul Scott, who they believe orchestrated Mr Brennan's kidnap and murder.

Paul Monk is one of the UK's most wanted fugitives (Image: PA)

Scott, 32, from Liverpool, was captured in December 2014 when he entered the UK in a light aircraft which landed on a remote rural airstrip in Norfolk.

Monk, from Romford, Essex, were arrested as part of Operation Captura, a drive launched in 2006 by the National Crime Agency, Crimestoppers and Spanish authorities to catch suspects who had fled from the UK.